It is unknown when the video was recorded. A source close to the family confirmed their identities to AFP.

France's foreign ministry said it was still trying to verify the authenticity of the video.

Foreign Minister Laurent Fabius said in a statement, "These images are terribly shocking. They display a cruelty without bounds."

Meanwhile, Prime Minister Jean-Marc Ayrault said the family was “probably” being held in Nigeria.

Cameroon's Communication Minister Issa Tchiroma Bakary said he could not comment because his government was not aware of the video.

The family, who were based in Cameroon, were visiting the Waza National Park when they were kidnapped on February 19. They have been identified as Tanguy Moulin-Fournier and his wife Albane, as well as their four sons, Eloi, Andeol, Mael and Clarence, aged between 5 and 12 years old.

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Tanguy's brother Cyril Moulin-Fournier was on vacation and with them at the time. The three adults are all around 40 years old.

The family, with the exception of the uncle, moved to Yaounde, Cameroon's diplomatic capital, in autumn 2011 when the father began a job there overseeing the construction of a liquid natural gas plant. The uncle lives in Barcelona, Spain.

Cameroonian and Nigerian soldiers are searching for them in the arid, rural border region the two countries share in West Africa.

More than 6,000 expatriates have settled in Cameroon yet these kidnappings mark the first time Westerners have been taken hostage in the western African country.